Gallon (US) per Second to Cubic Foot per Minute (gal/s to CFM)
Convert gal/s to CFM — Flow Rate converter
One gallon (US) per second equals 8.020833 CFM, so to convert gallons (US) per second to cubic feet per minute you multiply the value by 8.020833. A gallon (US) per second is larger than a cubic foot per minute — going the other way, 1 CFM = 0.12467532 gal/s. For example, 10 gal/s = 80.208333 CFM and 50 gal/s = 401.041667 CFM.
1 gal/s = 8.020833 CFM
Gallon (US) per Second to Cubic Foot per Minute formula
1 Gallon (US) per Second = 8.020833 CFM
Worked examples
- 25 gal/s = 200.520833 CFM
- 100 gal/s = 802.083333 CFM
Gallon (US) per Second to Cubic Foot per Minute conversion table
| Gallon (US) per Second (gal/s) | Cubic Foot per Minute (CFM) |
|---|---|
| 1 | 8.020833 |
| 2 | 16.041667 |
| 3 | 24.0625 |
| 5 | 40.104167 |
| 8 | 64.166667 |
| 10 | 80.208333 |
| 12 | 96.25 |
| 15 | 120.3125 |
| 20 | 160.416667 |
| 25 | 200.520833 |
| 50 | 401.041667 |
| 100 | 802.083333 |
| 250 | 2005.21 |
| 500 | 4010.42 |
| 1000 | 8020.83 |
Which gallon, and which trade
The single most expensive mistake in flow conversion is the gallon. A US liquid gallon is 3.785411784 litres; an imperial gallon is 4.54609 litres. US GPM and imperial GPM differ by about 20%, and pump datasheets frequently do not say which one they mean. Check the manufacturer's country of origin before trusting a GPM figure.
Different trades default to different units for the same physical quantity: HVAC and compressed air work in CFM, plumbing and pumps in GPM or LPM, and process and water engineering in m³/h or L/s. A specification that mixes them is usually quoting different equipment, not different flows. On this page, 1 gal/s = 8.020833 CFM.
CFM to metric is worth memorising: one cubic foot is exactly 0.028316846592 m³, so 1 CFM = 1.699011 m³/h and 1,000 CFM ≈ 1,699 m³/h. Note that CFM on a compressor may be quoted as free air delivery (FAD) at inlet conditions rather than at working pressure — the two are not interchangeable.
Frequently asked questions
How many cubic feet per minute are in one gallon (US) per second?
One gallon (US) per second equals 8.020833 cubic feet per minute (CFM).
How many gallons (US) per second are in one cubic foot per minute?
One cubic foot per minute equals 0.12467532 gallons (US) per second (gal/s).
How do you convert gallons (US) per second to cubic feet per minute?
1 Gallon (US) per Second = 8.020833 CFM. Use the calculator above for any value.
What is 5 gal/s in CFM?
5 gal/s = 40.104167 CFM.
What is 100 gal/s in CFM?
100 gal/s = 802.083333 CFM.
What is 10 gal/s in CFM?
10 gal/s = 80.208333 CFM.
What is 20 gal/s in CFM?
20 gal/s = 160.416667 CFM.
What is 50 gal/s in CFM?
50 gal/s = 401.041667 CFM.
What is 500 gal/s in CFM?
500 gal/s = 4010.42 CFM.
Is a gallon (US) per second bigger than a cubic foot per minute?
Yes. A gallon (US) per second is larger — one gallon (US) per second equals 8.020833 cubic feet per minute (CFM).